Current diesel engine valves open into the cylinder to provide air for combustion or to released exhaust gas after combustion. Most engine valves open into the cylinder and are timed either mechanically or electronically to avoid contact with the reciprocating piston that is moving up and down within the piston cylinder. These inward opening valves have the advantage of good sealing characteristics because, as cylinder pressures rise during combustion, the valve tends to seal more tightly against its seat because of the differential pressure on each side of the valve. The disadvantage, however, is that any mistiming of the valve opening event invites undesirable and potentially catastrophic valve to piston contact. This is due to the fact that both the piston and the valve member have the potential to attempt to occupy the same space at the same time.
Another disadvantage of prior art inward opening valves is their actuators and biasing springs tend to occupy a significant amount of space above the engine cylinder, leaving a relatively small envelope of space within which to position a fuel injector. Another disadvantage often encountered in these inward type opening valves of the prior art is that the biasing springs used to bias the valve to a closed position are often relatively strong. This requires a significant amount of energy and a powerful actuator to open each individual valve. This consequence in turn inhibits movement away from cam driven valves to a more desirable electronically actuated valving system.
The present invention is intended to alleviate these and other problems associated with the inward opening valving assemblies of the prior art.